1. Field of the Invention
The present invention relates to a photographing apparatus and a focusing control method, and specifically relates to a photographing apparatus having an automatic focus adjustment (AF control) function and a focusing control method.
2. Description of the Related Art
Japanese Patent Application Laid-Open No. 7-154669 discloses an automatic focus adjustment device employed in a still video camera, etc., the device comprising: an autocorrelation method-focusing device, and a hill climbing-method focusing device, the device, when a change in a subject after focusing is small, performing hill climbing-method focusing control, which has high focusing precision, and when a change in a subject after focusing is large, performing high-speed focusing control using the autocorrelation method, and then performing hill climbing-method focusing control to follow the change in the subject after focusing.
Conventionally, cameras configured so that AF control is performed for a subject in an AF area to be brought into focus when a focusing instruction is input, and after the AF control, an instruction to execute photographing and recording (photographing instruction) is input are known. Such a camera has a problem in that when a subject or the camera is moved during the time from a focusing instruction until a photographing instruction, the subject located within the AF area at the time of the input of the focusing instruction would fall outside the AF area at the time of the input of the photographing instruction, and the subject would become out of focus in an image actually photographed.
Japanese Patent Application Laid-Open No. 7-154669 above enables to follow a change in a subject at high speed using a combination of two types of focusing devices. However, the combination of two-types of focusing devices has a problem in that AF control processing becomes complicated. Also, Japanese Patent Application Laid-Open No. 7-154669 is not configured to focus on a particular subject, so it is different in AF control method from the present invention.